Safety cut-off valve for gas lines



March 5, 1929.

c. M. SMITH SAFETY CUT-QF? VALVE FOR GAS LINES Filed Sept. 16., 1926 Patented Mar. 5, 1929,

CHARLES M. sMIrH, or rior srn'rNGs, ARKANSAS, AssIGEon. 0E NrnE-TwENrIETHsf 'ro ARTHUR. JEFFERSON AND EnvE-TwENfriErHs 'ro sIEsEn HOWARD MATHEws,

BOTH OF HOT SPRINGS, ARKANSAS.

, y 71,704,633" im@ SAFETY our-ferr VALVE Een c-As LINEs.

.Appncaiion `ined september 1s, 192e. .serial iraisaeeilf This invention relates to safety' cut-olf valves for gas lines.

An important object of the invention is to provide a device of this character which is entirely automatic in itsoperation, in so 'far as cutting ofi' the gas supply is concerned, and which, when once positioned to cut. olf the gas supply, cannot be again opened without a manual operation. 1

A further object of the invention is to provide a valve including a cut olf element which, in the open position thereof, presents a relatively large area to the gas pressure, so that it is retained in open position and which, in

the closed position thereof, presents a small y area to the gas pressure, so that this gas pressure may not open the same. A

A further object of the invention is to provide a device of this character which may be readily and cheaply produced, which will be durable and eilicient in service and a general improvement in the art.

These and Vother Aobjects attain by the construction shown in the accompanying drawings, wherein for the purpose 'of illus-x tration is shown a preferred embodiment'of my invention and wherein Figure 1 is a vertical sectional view through a control valve'constructed in accordance` with my invention, the control bells being illlustrated in solid lines in position permitting passage of gases through the valve and in dotted lines in the cut-olf position; y i

Figure 2 is a section on the line 2 2 of Figure 1. K

Referring now more particularly to the drawings, the numeral 10 generally designates a casing having inlets 11 and 12 and an outlet 18. The inlets 11 and 12, only one of which is employed, the other being a plug, communicate with an axial tube 141 extending upwardly into the casing from the bottom thereof. About this tube is formed an annular chamber l15 for the reception of a sealing fluid, such as mercury. The upper end of the casing, for a purpose which will presently become obvlous, is enlarged, as at 16. Inwardly of the casing wall a second annular chamber 17 is formed,

the casingat its upper end enlarging at 18 to provide an enlargement of this chamber which is likewise intended for the reception of a sealing fluid. A cap 19 is provided for lthe casing and within the enclosure thus provided is mounted a bell 20, the side walls of which extendfinto the chamber 17 and are sealed bythe liquid therein. This' bell through a tubev 21 which opens through the upper end of the wall of the bell supports a smaller bell 22, the side walls of which are adapted to extend into the chamber 15 andbe sealed by the iuid contained therein when the bell 2O has lowered to a predetermined degree. The lower'end of the tube 21 is sealed to the bell 22 and the' upper end thereof is provided with a cap 23 through which is directed a stein 24 which loosely projects through an opening 25 formed in thecap'19 and is provided attlie outer face of the lcap with ahead 26. At its lower end," the stem24 is provided with a head 27 adapted to engage againstthe under face of the cap 23 and so provide a means for elevating the bells 2O and 22. About this stem 24 between the cap 23 and the inner face of the casingy cap 19 is a light spring 28, this spring merely serving to cushion the bell 2O and prevent its engagement with the casing capV 19 under the influence of the gas pressure.

The operation is as follows: When the bells 20 and 22are in the raised position, gas

may pass from either the inlets 11-or 12 to the outlet 13 'and its plied to both Vbells 2O and 22 to maintain these bells in elevated position. lf the gas pressure is cut off, for any reason, the bells20 and 22 will settle until the belll 22 enters the sealing fluid in the chamber 15. lt will now ybe obvious that if the gas pressure is again turned on through the inlets 11 or 12, pres sure will only beapplied to the bell-22 andl this pressure will be insuliicient to lift the bells. 1f, therefore, the gas cocks havebeen left opened during failure of the gas supply, there will be no unnoticed leakage, for it is necessary that the operator lift the bells .through the head 26 before a gas supply to bells '20 and 22 because of the weight of these pressure will be ap-' the burners or jets'can again be provided.

The enlargements 16 and 18 provide for the rise of the sealing iuid as the bells 20 andr 22 are moved downwardly thereinto.

vIt will be obvious that. the construction hereinbefore set forth is capable of a considerablevrange of change and modilication without materially 'departing from the spirit of the invention and l accordingly do'n'ot limit myself to such speciiic structure leX- cept as hereinafter claimed'.`

I claim l. In a Safety gas out-off valve and 1n com,-

Vbination, a casing having an inlet opening through and eXtendinO upwardly from' the bottom thereofya wall surroundingl the inlet and combining therewith to produce an'` open-topped chamber, the upperendoi the wall being flared to provide an enlargement ol' the chamber, a second wall arranged inwardly of and in spaced relationtothe casing` wall and combining therewith to produce an open-topped. chamber the upper end of which extends considerably above the uppery end oit the inlet, the easing` wall being enlarged to enlarge the upper end of said oh arnber, a pair of bells within the casing' and hav-y ing` their lower ends adapted for extension Ainto Said chambers, said bells' being conneted for simultaneous. inoven'ient, and an outlet for the casing at the bottom thereof, Chambers having a ,sealing` fluid therein.

2. In a safety gas cut-oill Avalve and in combination, a casing havingl an inlet openingl through and extending upwardly from lthe bottom thereof, a wall surrounding the inlet and combining therewith to produce an opentopped chamber, the upper end of the wall being flared to provide'an enlargement of the chamber, a second wall arranged inwardly ot' and in spaced relation to the casing wall and combining therewith to produce an open-topped chamber the upper end oi which extends considerably above the upper end of the inlet, the yeasing,` wall being enlarged to enlarge the upper end of said chamber,` a pair of bells within the casing` and havingv tube and provided at its lower end with ahead and a spring,I surrounding the rod between. the'casing top and said cap. i

In testimony whereorpv I hereunto afzg my signature.

CHARLES M. Sarra.y 

